Diaryl containing wax-like solid



Patented Jan. 17, 1 933 UNITED STATES.

PATENT 7 OFFICE CHARLES B. DURGIN AN D RUSSELL L. JENKINS, OF ANNISTOH,ALABAMA, ASSIGHOBS TO SWANN RESEARCH, INC A CORPORATIOR OF ALABAMADIARYL CONTAINING WAX-LIKE SOLID In Drawing.

This invention relates to a new diarylcontaining wax-like solid.

It has been known that when benzol is assed through a red-hot tube,diphenyl is ormed. The composition of the product produced in this wayvaries with the temperature of the hot tube, the filling material usedin the tube, the velocity of the vapors and the presence of such gasesas hydrogen n or nitrogen mixed with the benzol. We have discovered thatfurther variation in the composition of the product is obtained whensuch com ounds as toluene and Xylene arepres ent in the benzol treatedin this manner, and that highly condensed complex hydrocarhens areformed.

It has recently been discovered that when benzol is passed through abath of molten lead, heated to a temperature about 700 0.,

o diphenyl and hydrogen are formed. However, it has not heretofore beenknown so far as we are aware, that't'he'complex products mentioned aboveare roduced together with diphenyl in the lea bath method of treatingbenzol, nor how the composition of the product could be varied at will;It is one of the objects of this invention to provide a newdiaryl-containing wax-like solid of high boilin point.

A irther object of this invention is to provide a means whereby thecomplex character of the product as determined by the boilin points ofits various fractions can be varie at will. A still further object ofthis invention is to provide a product which is useful in producing achlorinated diaryl which does not become crystalline at the higherchlorine content.

These objects are accomplished, in the fol- 1o lowing manner: We havediscovered that when benzol. is passed into andthrough a bath of moltenlead heated to between 700 and 800 0., considerable amounts of diphenyltogether with a mixture of more complex hydrocarbons are formed. We havefurther Application filed September 27, 1929. Serial No. 398,084.

found that the amount of the more complex hydrocarbon can be materiallyincreased by increasing thetemperature of the lead bath, and also bychanging the composition of the benzol used as a starting material.Further, we have found that the material thus produced is of greatvalue, since when chlorinated its tendency to crystallize is greatlyminimized.

The particular'manner in which our invention may be carried out and thenew product produced may be illustrated by the following examples:

Eceo/mple I Commercially pure liquid benzol which distils within a rangeof 2 C. is pumped through a coil of pipe which is immersed in a bath ofa molten substance inert with re spect to the benzol, such as lead oraluminum, and which is maintained at the maximum temperature at whichsubstantially no di phenyl is formed. This coil acts as a preheater andserves to vaporize the liquid benzol and preheat the henzolw vapor to apoint in the neighborhood of the diphenyl formation temperature.

The coil which is at the bottom of the bath is perforated, and the vaporstreams out and in rising through the molten sub- I stance, in physicalcontact therewith, agitates the bath in such a manner as to maintain apractically uniform temperature throughout the bath. By employing alarge mass in the bath, we are enabled to prevent over-heating of thevapor due-to the heat capacity of the bath, and by means of athermocouple immersed therein to observe temperature changes which mayoccur and this is the optimum temperature range for continuousoperation.

After the preheated vapor emerges from the preheater bath, it isimmediately passed into a converter bath which is of similar design andarrangement as the preheater. The vapor passes to the bottom of the bathand streams out through holes in a distributor, and then bubbles upthrough the bath in a manner similar to that described for thepreheater. The converter bath is kept at a temperature range of from 750to 850, referably around the latter temperature. on the vapor passesfrom the converter bath it is passed, at a high velocity, directly intoa water-cooled condenser, so constructed that the vapor is quicklycooled and the unconverted benzene and the diphenyl are condensed andcollected, while the hydrogen which is liberated when diphenyl is formedis vented through a water seal.

We have found that when operating in this manner with commercially purebenzole, the percentage of crude diphenyl (i. e., the

percent of the fraction boiling between 200 and 270 C.) with 750 C.converter temperature is approximately 4.5% of the total condensate,while the fraction boiling above 270 C. is approximately 0.4% of thetotal.

If now the converter temperature be raised to 800 (1, the crude diphenylfraction (200- 270 C.) increases to approximately 8% of the totalcondensate, while the high-boiling fraction (above 270 C.) increasesapproxi- 3 inately to 1% of the total. By further increasing thetemperature to 850 C., the crude diphenyl fraction increases toapproximately 15.5% of the total condensate, while the highboilingfraction increases to approximately 5% 0f the total.

Example I I Instead of the commercially pure benzol used in Example I,pass commercial benzol through the converter units described in exampleI, and exactly in the same manner. Commercial 90% benzol containscertain percentages of other aromatic hydrocarbons, especially tolueneand xylene. It is identified by its distillation range. For example, itstarts distillation at 762 (3.; dis tils up to C.; and all distils belowC. 55 The new product formed in this case is somewhat different incomposition from that formed in Example I.

In the following table, these products are compared. These results wereobtained by so fractionally distilling the new product ob tained asheretofore outlined (boiling above 200 G.) into two fractions, onedistilling between 200 C. and 270 C. and the second distilling above 270 C. The latter fraction 05 (above 270 C.) is termed high boilingcompound while the fraction boiling between 200 and 270 C. is termedmainly diphenyl.

Example [[1 High-boiling compound (above 270 C.) in new roduct (above200Bath temperature Commer- Commerclal 90 per 0181 benzol cent benzol isnot suitable or is too expensive. It may also be chlorinated and anon-crystalline solid obtained which is fire-retarding and has excellentproperties making it valuable for electrical insulating purposes.

The advantages of this invention are that a new product containingvarying amounts of high-boiling substances may be cheaply produced. Thenew product may have a varying composition which is obtained at will byvarying the starting materials or the temperature of the reactions. Thevalue of the new product lies in the fact that the physical propertiesof the diphenyl-containing product may be varied at will within therange above set out.

The new product distills above 200 C.

and is comprised of two classes of compound,-

namely, crude diphenylboiling between 200 and 270 and high boilingcompound boiling above 270 and below the decomposition temperature ofthe compound which is in the neighborhood of 350 to 400 C.

\Vhat we claim is:

1. The process for producinga diphenyl 700 C. and 800 0., condensing theresulting vapors and heating said condensate to 200 C. to-remove lowboiling constituents.

3. The process for producing a diphenyl containing wax-like solid,comprising volatilizing benzol admixed with substantial quantities oftoluol and xylol, contacting said vapor with a fluid'mass maintained atdiphenyl forming temperatures, condensing the resulting vapors andheating said con densate to 200 C. to remove low-boiling constituents.

4. The process for producing a diphenyl containing wax-like solid,comprising volatilizing commercial 90% benzol, contacting the thusformed vapors with an inert liquid mass maintained at diphenyl formingtemperatures, condensing the resulting vapors and heating saidcondensate to remove hydrocarbons boiling below 200 C.

5. The process for producing a diphenyl containing wax-like solid,comprising volatilizing commercial 90% benzol, contacting the thusformed vapors with molten lead maintained at diphenyl forming temperatures, condensing the resulting vapors and heating said condensate toremove hydrocarbons boiling below 200 C. 6. In a process of producingdiphenyl by thermal synthesis from benzol by contacting benzol with aheated inert molten substance,

the step of controlling the percentage of com plex hydrocarbons boilingabove 27 0 C. by

controlling the temperature of said substance.

v 7. In a process of producing diphenyl by thermal synthesis from benzolby contacting benzol with a heated inert molten substance, the step ofcontrolling the percentage of complex hydrocarbons boiling 'above 270 C.by maintaining the temperature of said substance at above 800 C. p 8. Ina'process of producing diphenyl by thermal synthesis from benzol bycontacting benzol with a heated inert molten substance comprisingvaporizing commercial 90% benzol, and subjecting the vapors by contactwith said molten substance to a temperature of from 800 to 850 C. toincrease the production (23f complex hydrocarbons boiling above 270 a 9.In a process of producing diphenyl by thermal synthesis from benzol bycontacting benzol with a heated inert molten substance comprising,vaporizing a mixture of commercial benzol and commercial benzol,

and subjecting the vapors by contact with said molten substance to atemperature of from 800 to 850 C. to increase'the produ'ction of complexhydrocarbons boiling above 270 C. In testimony whereof we aflix oursignatures.

CHARLES B. DURGIN. RUSSELL L, JENKINS.

